Emergency control system and method for braking failure of distributed driving new energy vehicle model

Abstract

The invention provides an emergency control system and method for distributed driving new energy vehicle type braking failure. The method comprises the steps that according to the braking failure type, reverse driving torque needed for compensating for braking force deficiency caused by a failure loop or insufficient assistance is calculated; the ideal yaw velocity and the actual yaw velocity of the vehicle are obtained, and the reverse yaw moment is calculated through a PID control algorithm so as to restrain unexpected yaw in the braking process; according to the reverse driving torque and the reverse yawing torque, the final driving torque of each driving wheel is calculated; and the final driving torque of each driving wheel is used for controlling the distributed driving motor to output corresponding reverse driving force. By means of the method and system, when a new energy vehicle fails in braking assistance or a single circuit fails, enough deceleration can be obtained, the vehicle is kept stable, and therefore the safety of the vehicle and personnel is guaranteed.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of vehicle brake failure emergency control, and particularly relates to an emergency control system and method for distributed drive new energy vehicle models in brake failure. BACKGROUND

[0002] Currently, the braking demand of a vehicle is mainly realized through a hydraulic braking system. The braking action of the system can be triggered by the driver stepping on the brake pedal or actively triggered by the vehicle electronic control system (such as ESP, intelligent driving system, etc.) according to the driving conditions. For passenger cars, the hydraulic braking system usually adopts an X-type arrangement scheme, such as one circuit for the left front and right rear and another circuit for the right front and left rear. This scheme can retain 50% of the braking efficiency when a single circuit fails. However, the existing vehicle braking system still has significant technical defects when facing brake failure, as follows: For general vehicle models, when the booster system fails or a single circuit system fails, the driver needs to directly promote the wheel brake with a large pedal force, and only a partial deceleration can be obtained, which is difficult to meet the emergency braking demand. If the single circuit system fails, the vehicle can only rely on the remaining single circuit for braking, which not only lacks deceleration but also causes the vehicle to yaw during braking due to the difference in braking force between the front and rear single sides under the X-type arrangement, seriously affecting the driving stability.

[0003] For L3 and above levels of automatic driving systems, although a brake redundancy system (to ensure safe parking when a single point fails) is provided, the system still has shortcomings in the single circuit failure scenario: it can only provide partial deceleration, and also causes vehicle yaw due to uneven distribution of braking force, which cannot completely guarantee the stability and safety during braking.

[0004] In summary, whether it is a conventional vehicle or an intelligent driving vehicle, when encountering brake booster failure, single circuit failure, etc., there are problems of insufficient braking efficiency and easy yawing of the vehicle, which is difficult to meet the safe parking demand in emergency situations, posing a serious threat to personnel and vehicle safety. Therefore, a new technical solution is needed to solve the above-mentioned defects of the prior art. SUMMARY

[0005] To solve the problem of insufficient braking efficiency or poor vehicle stability caused by various brake failures during the driving of a conventional vehicle or an intelligent driving vehicle, the present application proposes an emergency control system and method for distributed drive new energy vehicle models in brake failure.

[0006] An emergency control system for distributed drive new energy vehicle models in brake failure, which achieves one of the purposes of the present application, comprises: feedforward torque calculation module: for calculating the reverse driving torque required to compensate for the loss of braking force according to the brake failure type; feedback torque calculation module: for obtaining the ideal yaw rate and the actual yaw rate of the vehicle, and calculating the reverse yaw torque through the PID control algorithm to suppress the unintended yaw during braking; comprehensive calculation module: for calculating the final driving torque of each driving wheel according to the reverse driving torque and the reverse yaw torque; the final driving torque of each driving wheel is used to control the corresponding reverse driving force output by the distributed drive motor.

[0007] The technical effects of the above technical solution include: breaking through the limitation of traditional independent braking system, realizing real-time data interaction between IPB (braking system) and PDCU (driving system) through chassis domain controller, making the driving motor quickly transform into a brake auxiliary source when brake failure occurs, and forming a composite braking mode of hydraulic braking + motor reverse driving. The feedforward control directly compensates for the loss of braking force based on the hydraulic signal, and the feedback control dynamically corrects through the yaw rate, and the two work together to realize precise control of static compensation + dynamic correction, which greatly improves the yaw suppression effect compared with the traditional single closed-loop control. Among them, the real-time data interaction between the chassis domain controller and IPB, PDCU relies on the communication link commonly configured in the vehicle to realize, which conforms to the common design specification of vehicle electronic system and can meet the basic needs of daily data transmission; the composite braking mode combining hydraulic braking and motor reverse driving is also a function cooperation based on the existing hardware architecture of distributed drive new energy vehicle, without the need to increase special hardware equipment to support the preliminary operation of the mode. It can make the distributed drive new energy vehicle obtain sufficient deceleration and remain stable when brake failure occurs, avoid unintended yaw, and ensure the safety of the vehicle and personnel. It solves the problem that the conventional vehicle or intelligent driving vehicle in the prior art has insufficient deceleration, low braking efficiency, and yaw when a single loop fails, which is difficult to ensure safety.

[0008] Further, when the brake failure type is IPB single loop failure, the calculation method of the reverse driving torque includes: According to the IPB master cylinder hydraulic signal, the brake parameters of the front brake circuit and the rear brake circuit, the reverse driving torque M 前 and the reverse driving torque M 后 of the front brake circuit are calculated. The driving motor on the brake failure side respectively provides the reverse driving torque equal in size to M 前 and M 后 .

[0009] The technical effects of the above technical solutions include: for the IPB single loop failure scenario, the reverse driving torque provided by the failed side motor is calculated based on the non-failed loop parameters, which can compensate for the loss of braking force caused by single loop failure, solving the problem of insufficient deceleration when the single loop of the prior art fails. The collection components of the non-failed loop parameters include the original IPB master cylinder pressure sensor of the vehicle, the caliper parameter pre-stored database, etc., without the need for additional sensors or storage modules; the torque output instruction of the failed side motor is transmitted through the conventional control signal link between PDCU and the drive motor, and the communication protocol of this link is consistent with the conventional communication protocol of the vehicle driving system, without the need for separate development of special communication interfaces. For example, when the right front + left rear loop fails, the non-failed left front + right rear loop provides a 0.4g deceleration through hydraulic braking, and the failed side left front and right rear motors supplement a 0.4g deceleration through reverse driving torque, with a total deceleration of 0.8g, consistent with normal braking efficiency.

[0010] Further, the calculation method of the reverse driving torque includes: M 前 =P1×A 前 ×BF 前 ×r 前 / R; M 后 =P1×A 后 ×BF 后 ×r 后 / R; M 前 and M 后 represent the reverse driving torque corresponding to the front brake circuit and the reverse driving torque corresponding to the rear brake circuit, respectively; A 前 and A 后 : represent the front caliper piston area and the rear caliper piston area, respectively; BF 前 and BF 后 : represent the front caliper efficiency factor and the rear caliper efficiency factor, respectively; calibrated through bench testing; r 前 and r 后 : represent the front caliper effective action radius and the rear caliper effective action radius, respectively; R: tire rolling radius.

[0011] The technical effects of the above technical solutions include: by quantifying the reverse driving torque calculation when the single loop fails, the compensation torque calculation is more accurate, ensuring that the reverse driving torque output by the failed side motor can accurately make up for the braking force of the non-failed loop, and ensuring the braking efficiency. The problem of large deceleration fluctuation caused by lack of accurate braking force compensation calculation when the single loop fails in the prior art is solved.

[0012] Further, when the brake failure type is assist failure, the calculation method of the reverse driving torque includes: According to the output hydraulic pressure P 正常 of the same input when the assist is normal 失效 , the brake parameter calculation of the front brake circuit and the rear brake circuit provides the reverse driving torque of the front and rear wheels through the driving motor. Wherein, the same input refers to the same brake pedal stroke, for example, the pedal stroke S1=50mm, the output hydraulic pressure P 正常 =80bar when the assist is normal, and the output hydraulic pressure P 失效 =30bar when the assist fails. The pressure difference of 50bar is the hydraulic loss amount that needs to be compensated.

[0013] The technical effects of the above technical solutions include: for the assist failure scene, the reverse driving torque is calculated according to the hydraulic pressure difference when the assist is normal and when the assist fails, which can effectively make up for the loss of braking force caused by insufficient assist, and solve the problem of large manual brake pedal force and insufficient deceleration when the assist fails in the prior art. For example, when the assist fails, the hydraulic pressure generated by the driver applying the pedal force is smaller than the normal value, but after the torque corresponding to the hydraulic pressure is compensated by the motor, the pedal force does not need to be increased, which greatly reduces the operation strength of the driver.

[0014] Further, the calculation method of the reverse driving torque includes: M 前 =(P 正常 -P 失效 )×A 前 ×BF 前 ×r 前 / R M 后 =(P 正常 -P 失效 )×A 后 ×BF 后 ×r 后 / R A 前 and A 后 : represent the front caliper piston area and the rear caliper piston area respectively; BF 前 and BF 后 : represent the front caliper efficiency factor and the rear caliper efficiency factor respectively; r 前 and r 后 : represent the front caliper effective action radius and the rear caliper effective action radius respectively; M 前 and M 后 are the required reverse driving torque of the front wheel and the required reverse driving torque of the rear wheel respectively; R: tire rolling radius.

[0015] The technical effects of the above technical solutions include: through the quantitative calculation of the reverse driving torque when the assist fails, it is ensured that the reverse driving force output by the driving motor can make the vehicle obtain ideal braking torque, and the braking efficiency is improved; the problem that in the prior art, when the assist fails, the missing amount of braking force cannot be accurately quantified, resulting in unstable braking efficiency, is solved.

[0016] Further, the calculation method of the final driving torque includes: The reverse driving torque output by the feedforward torque calculation module and the reverse yaw torque output by the feedback torque calculation module are vector superimposed according to the corresponding drive wheels to obtain the final driving torque of each drive wheel and output to the PDCU.

[0017] The vector superposition in the present solution specifically refers to the reverse driving torque M 前 , M 后 output by the feedforward control and the reverse yaw torque output by the feedback control are distributed to each drive wheel according to a preset proportion according to the corresponding relationship between the drive wheel and the failed loop (for example, when a single loop fails, the left front and the right rear are the failed side drive wheels), and then the torques are superimposed, for example, the left front wheel bears 1 / 2 of the reverse yaw torque, and the right rear wheel bears -1 / 2 of the reverse yaw torque, and finally the final driving torque of each drive wheel is obtained.

[0018] The technical effects of the above technical solutions include: through the method of vector superimposing the reverse driving torque and the reverse yaw torque to obtain the final driving torque, both sufficient deceleration and inhibition of unintended yaw during braking are ensured, and the vehicle stability is maintained; the problem of yaw caused by asymmetric braking force when a single loop fails in the prior art is solved.

[0019] Further, it further includes a driving torque adjustment module for adjusting the driving torque according to the wheel slip ratio, and the adjustment method includes: adjusting the driving torque when the wheel slip ratio exceeds the set limit value. The technical effects include: it can prevent the wheel from locking due to excessive driving torque, avoid vehicle out of control during braking, and further ensure the braking stability. The real-time monitoring of the wheel slip ratio is derived from the wheel speed sensor and the GPS / IMU fusion system already equipped in the vehicle, without the need for additional installation of a special slip rate detection device. The sampling frequency of the sensor data is consistent with the conventional sampling period of the chassis domain controller, ensuring that the monitoring process is coordinated with the operation rhythm of the vehicle electronic system. The dynamic adjustment instruction of the driving torque is transmitted to the PDCU through the existing CAN FD communication bus of the vehicle, without the need for separate development of a dedicated communication link. The slip rate set limit value is also pre-stored in the vehicle model parameter library of the chassis domain controller, which is compatible with the basic hardware configuration of the vehicle braking system, without the need for additional complex parameter calibration operations during system deployment.

[0020] Further, the method for adjusting the driving torque according to the wheel slip ratio comprises: when the slip ratio exceeds a set upper limit value, reducing the driving torque according to a set slope; and the technical effects comprise: when the slip ratio exceeds the upper limit, the driving torque is reduced according to the set slope, which can quickly inhibit the excessive wheel slip, prevent the vehicle from skidding or fishtailing, and improve the safety during emergency braking. The problem that the wheel may be locked due to the excessive driving torque when the brake fails in the prior art is solved.

[0021] Further, the method for adjusting the driving torque according to the wheel slip ratio further comprises: when the wheel slip ratio is below a set lower limit value, restoring the final driving torque of each driving wheel. The technical effects comprise: after the slip ratio is restored to the lower limit, the original driving torque is restored, which can continuously provide sufficient braking force under the premise of ensuring the braking stability, ensure that the vehicle can be timely decelerated and parked, and balance the braking efficiency and stability. The problem that the braking efficiency is low and the stability is poor when the brake fails in the prior art is solved. Further, the method further comprises an invalidation detection module for monitoring the state of the brake system in real time, identifying the single-loop invalidation or the assist invalidation of the IPB, and generating a corresponding invalidation signal and sending the signal to the communication bus. The technical effects comprise: by monitoring the state of the brake system in real time and identifying the brake invalidation type, the corresponding invalidation signal can be timely generated and sent, which provides a premise and basis for the subsequent targeted work of the feedforward torque calculation module and the feedback torque calculation module, and ensures that the system can quickly respond to different types of brake invalidation. The problems that one of the prior arts only relies on manpower or single-loop braking when the single-loop or assist invalidation occurs and has no effective identification mechanism, and the other prior art cannot deal with the invalidation type although it has redundancy are solved, which ensures the timeliness and accuracy of the emergency control strategy and lays a foundation for the vehicle to obtain sufficient deceleration and remain stable when the brake fails.

[0022] The second aspect of the present application is an emergency control method for a distributed driving new energy vehicle when the brake fails, which comprises: calculating a reverse driving torque required for compensating for the lack of braking force according to the brake invalidation type; acquiring an ideal yaw rate and an actual yaw rate of the vehicle, calculating a reverse yaw torque through a PID control algorithm, and inhibiting the unintended yaw during braking; calculating a final driving torque of each driving wheel according to the reverse driving torque and the reverse yaw torque; and the final driving torque of each driving wheel is used to control the distributed driving motor to output a corresponding reverse driving force.

[0023] The third aspect of the present application is a non-transitory computer readable storage medium having a computer program stored thereon, wherein the computer program is executed by a processor to implement the steps of the emergency control method for a distributed driving new energy vehicle when the brake fails.

[0024] A computer program product for achieving the fourth objective of the present invention includes a computer program / instruction that, when executed by a processor, implements the steps of the emergency control method for brake failure in a distributed-drive new energy vehicle.

[0025] The beneficial effects of this invention include: This invention addresses the issues of insufficient deceleration and low braking efficiency in conventional vehicles or autonomous vehicles under scenarios such as single-loop failure and power assist failure. It employs feedforward control to precisely calculate and compensate for the loss of braking force, ensuring sufficient deceleration even in the event of brake failure, thus avoiding the risk of being unable to stop in time during emergencies. Regarding the vehicle yaw problem caused by the X-shaped layout and differences in braking force during single-loop failure, feedback control calculates a reverse yaw torque based on the yaw rate difference. Combined with the feedforward torque output, this ensures vehicle stability during braking, preventing unexpected yaw from affecting driving safety. Furthermore, through the collaboration of the chassis domain controller with systems such as the PDCU and IPB, this invention utilizes the drive system to provide a reverse driving torque to assist braking in the event of single-point or multi-point braking failure, forming a cross-system redundancy solution suitable for new energy vehicles, comprehensively ensuring the safety of the driver and the vehicle. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the system described in this invention; Figure 2 This is a schematic diagram of the driving torque output when a single loop fails. Figure 3 This is a schematic diagram of the driving torque output when the booster fails. Detailed Implementation

[0027] The following detailed embodiments are provided to explain the technical solutions of the present invention, so that those skilled in the art can understand the present invention. The scope of protection of the present invention is not limited to the following specific embodiments. Any modifications or improvements made by those skilled in the art that incorporate the technical solutions of the present invention but differ from the following detailed embodiments are also within the scope of protection of the present invention.

[0028] An emergency control method for brake failure in a distributed-drive new energy vehicle includes: For vehicles using IPB (Intelligent Integrated Brake Control System), when a single loop of IPB fails, a single-loop brake assist failure signal is sent to the CAN bus. The chassis domain controller monitors the signals on the CAN bus in real time (e.g., every 10ms). When the chassis domain controller detects a single-loop brake assist failure signal on the CAN bus, it will perform the following control actions: A. Feedforward control: In one embodiment, when the left front and right rear brakes fail, the chassis domain controller calculates in real time the braking torque M of the single-loop right front / left rear wheels that are still braking, based on the IPB master cylinder hydraulic signal P1. 前 / M 后 The chassis domain controller controls the PDCU (Power Domain Controller), and the reverse drive torque M is provided by the left front / right rear drive motor on the brake failure side. 前 / M 后 M 前 / M 后 The calculation can be performed using the following formula: M 前 =P1×A 前 ×BF 前 ×r 前 / R; M 后 =P1×A 后 ×BF 后 ×r 后 / R; In the formula: A 前 and A 后 : These represent the piston areas of the front and rear calipers, respectively; determined based on recommended values ​​in the caliper supplier's technical manual to ensure they match the actual braking performance of the calipers; BF 前 and BF 后 : These represent the front caliper performance factor and the rear caliper performance factor, respectively; calibrated through bench testing as specified in national standards; r 前 and r 后 : These represent the effective working radius of the front caliper and the effective working radius of the rear caliper, respectively; they are determined by the distance from the center of the caliper friction pad to the center of rotation of the brake disc, and are obtained by measurement through the caliper's three-dimensional model; Based on the failed single circuit, determine the corresponding left front and right rear brake failure sides, and control the drive motor on the failure side to provide power to M. 前 / M 后 Equal and opposite driving torques; In one embodiment, when the right front and left rear brakes fail, the same method described above is used to calculate the reverse driving torque M. 前 / M 后 The right front / left rear drive motor on the brake failure side provides reverse drive torque M 前 / M 后 The formula will not be elaborated here.

[0029] In one embodiment, when a hydraulic line ruptures or the IPB motor completely fails, the IPB experiences a dual-circuit failure. At this time, there is no hydraulic braking force, and the master cylinder hydraulic signal P1 cannot be obtained. Instead of relying on the hydraulic signal P1, the total reverse driving torque M is calculated based on the expected deceleration corresponding to the driver's brake pedal travel, combined with the vehicle's current speed and axle load. 总 = (m × a × R) / (η × BF_avg), where a is the desired deceleration; m is the vehicle mass; η is the motor transmission efficiency; and BF_avg is the average caliper efficiency factor. The load is then distributed to each drive wheel according to the axle load ratio. Front / rear axle load ratio = actual weight carried by the front / rear axle / total vehicle weight. The axle load ratio is collected by front and rear axle load sensors. For example, when fully loaded, the front axle load is 1000kg, the rear axle load is 800kg, and the total weight is 1800kg. The front axle load ratio = 1000 / 1800 ≈ 0.556, and the rear axle load ratio = 800 / 1800 ≈ 0.444. Torque is distributed to the front and rear axle drive wheels according to this ratio.

[0030] In one embodiment, the desired deceleration 'a' is set based on the brake pedal travel; for example, a = 0.3-0.5g corresponds to a travel of 0-50mm, a = 0.5-0.8g corresponds to a travel of 50-100mm, and a = 0.8-1.0g corresponds to a travel of 100-150mm. This can be calibrated by conducting multiple tests on a real vehicle.

[0031] In one embodiment, the caliper performance factor (BF) decreases due to thermal degradation of the caliper friction pads at high temperatures. Therefore, in one embodiment, the caliper performance factor is further corrected, and the correction method includes: BF 修正 =BF 标定 × (1-kT×ΔT), where ΔT is the difference between the actual caliper temperature and the caliper temperature (e.g., 25℃), and kT is the temperature coefficient, calibrated through actual vehicle testing. The temperature coefficient at low temperatures is less than that at high temperatures. ΔT is acquired by the temperature sensor built into the caliper, with an accuracy of ±1℃, a sampling period of 50ms, and a temperature acquisition range of -40℃ to 150℃, meeting the requirements for use in extreme climates.

[0032] B. Feedback Control: The chassis domain controller calculates the reverse yaw torque that provides stability control based on the difference between the ideal yaw rate ω0 and the actual yaw rate ω using PID control. The ideal yaw rate ω0 is calculated using a classic vehicle dynamics model based on the current vehicle speed, steering angle, and body parameters. This model uses a two-degree-of-freedom approach, ignoring roll and pitch effects, making it suitable for real-time control. Model parameters (such as wheelbase L and center of gravity height h) are pre-stored in the controller and automatically retrieved according to the vehicle configuration. The actual yaw rate ω is collected in real-time by a vehicle yaw rate sensor. The yaw rate sensor has a measurement range of ±200° / s, an accuracy of ±0.1° / s, and a sampling frequency of 100Hz, meeting electromagnetic compatibility requirements and ensuring data accuracy in complex electromagnetic environments.

[0033] The methods for calculating yaw moment include: The difference between the ideal and actual yaw rate is calculated as Δω = ω - ω0 or ω0 - ω, depending on the control direction definition. When the actual yaw rate ω is greater than the ideal value ω0, Δω is positive, and a positive reverse yaw torque needs to be output to suppress the yaw. Otherwise, a negative yaw torque is output. The control direction definition is determined through actual vehicle testing to ensure that the yaw suppression direction is correct.

[0034] The error value Δω is input into the PID controller, and through iteration, a counter-yawing torque is finally obtained to suppress yawing, thus achieving vehicle stability control. The compensation torque is dynamically output by processing the yawing angular velocity deviation in real time.

[0035] C. Driving torque output: Calculate the torque M1 / M2 (i.e., M) output from the feedforward control. 前 / M 后 The final driving torque M1' / M2' of each drive motor is determined by vector superposition of the yaw torque and the reverse yaw torque, and then the final driving torque is output to the PDCU. See details. Figure 2 .

[0036] D. Slip ratio closed-loop control: When the slip ratio of the drive motor-controlled wheel exceeds the limit E, the driving torque is reduced according to the set slope; when the slip ratio recovers to below the limit F, the original control strategy continues to be used; the set slope can be dynamically adjusted according to the current vehicle speed and road surface adhesion coefficient (such as dry road surface, icy and snowy road surface). For example, a smaller slope is used on low adhesion coefficient road surfaces to avoid wheel lock-up.

[0037] In one embodiment, when the right front + left rear braking circuit fails, the specific implementation method includes: At t=0ms, the IPB detects that the pressure in the right front + left rear loop remains below the set value of 0.5 bar for 30ms. The IPB pressure sensor has an accuracy of ±0.5 bar and a response time of <10ms, sampling every 1ms. Failure is only determined after all 30 sampling points (30 ms) are below 0.5 bar, avoiding false alarms caused by instantaneous pressure fluctuations. Furthermore, the wheel speed deviation is 30%, exceeding the set deviation value of 20%. Therefore, the right front + left rear loop is determined to be faulty, and a signal indicating a failure in the right front + left rear assist circuit is sent via CAN FD. The wheel speed deviation is calculated as (failed wheel speed - non-failed wheel speed) / non-failed wheel speed × 100%. The CAN FD transmission cycle is 10ms, and the signal includes the faulty loop identifier, failure timestamp, and pressure value, ensuring the chassis domain controller fully acquires the failure status.

[0038] When t=10ms, the chassis domain controller receives a signal indicating a failure of the right front + left rear power steering circuit. It then reads the IPB master cylinder pressure P1 as 80 bar and calculates it using the following formula: M 前 =80×50cm²×0.85×0.12m / 0.3m=80×50×10⁻ 4 m²×0.85×0.12 / 0.3=1.02kN·m; M 后 =80×40cm²×0.75×0.10m / 0.3m=80×40×10⁻ 4 m²×0.75×0.10 / 0.3=0.4kN·m; Left front motor compensation value: M 前 × Redundancy coefficient (1.2) = 1.224 kN·m, Right rear motor compensation value: M 后 × Axle load factor (0.9) = 0.36 kN·m; The redundancy factor is used to correct the torque and compensate for uncertainties in braking system parameters, such as hydraulic signal errors, motor torque output deviations, and caliper efficiency factor fluctuations, to ensure sufficient braking force compensation and avoid insufficient braking performance due to parameter deviations. In this embodiment, the redundancy factor of 1.2 can cover 10% of the error and reserve a 10% safety margin to ensure sufficient braking force compensation, but it is not limited to this value. The axle load factor of 0.9 corresponds to a rear axle load ratio of 0.45. Since the rear axle load is lower than the front axle and has a weaker load-bearing capacity, it is multiplied by 0.9 to reduce the torque and avoid overloading the rear axle motor.

[0039] At t=20ms, the ideal yaw rate ω0=3° / s, the actual yaw rate ω=9° / s, and the calculated yaw rate deviation Δω=6° / s; the PID calculates the reverse yaw torque M according to the following formula. z_feedback : M z_feedback ==Kp ×Δω+K i × +K d × =1500×6+80×∫6dt+300×d(6) / dt≈9000N·m; Ultimately, the final torque of the left front motor = the compensation value of the left front motor + the reverse yaw torque M z_feedback =1.224kN·m+9000N·m / 2=1.224+4.5=5.724kN·m; The final torque of the right rear motor = the compensation value of the right rear motor + the yaw torque in the opposite direction M z_feedback =0.36kN·m-9000N·m / 2=0.36-4.5=-4.14kN·m; The negative sign indicates that the torque direction is opposite to the feedforward torque, which is used to counteract the yaw tendency; the right rear motor supports bidirectional torque output.

[0040] At t=50ms, assuming the left anterior slip ratio reaches 28%, exceeding the set limit E=25%, it is reduced to 5.5kN·m at a slope of 50N·m / ms. After the slip ratio recovers to 22%, the output is maintained. During the output maintenance period, the slip ratio is monitored every 10ms. If it exceeds the limit again, the adjustment is repeated to ensure that the slip ratio is always controlled within the 20%-25% range.

[0041] In one embodiment, for vehicles employing IPB (Intelligent Integrated Brake Control System), when IPB experiences power assist failure, it sends a power assist failure signal to the CAN bus. The chassis domain controller monitors the CAN bus signal in real time (e.g., every 10ms). When the chassis domain controller detects this signal, it performs the following control actions: A. Feedforward control: When the vehicle's power steering is functioning normally, the IPB input stroke and IPB output hydraulic pressure satisfy a specific curve. Specifically, when the IPB input stroke is S1, the IPB output hydraulic pressure is P1; when the power steering fails, when the IPB input stroke is S1, the IPB output hydraulic pressure is P1' (P1' < P1). This specific curve represents the correspondence between the IPB input stroke and output hydraulic pressure, calibrated experimentally before the vehicle leaves the factory. It is pre-stored in the chassis domain controller and can be directly retrieved when the power steering fails. This correspondence can be obtained using polynomial fitting, such as: P = 0.02S² + 0.5S + 0.3 (S: mm, P: bar). The fitting data comes from multiple bench tests, with a goodness of fit R² = 0.998, ensuring a lookup error ≤ ±3 bar.

[0042] To achieve the ideal braking torque, the chassis domain controller controls the PDCU (Power Domain Controller), which provides the front and rear wheels with opposing driving torque M via the drive motor. 前 / M 后M 前 / M 后 The calculation can be performed using the following formula: M 前 =(P1-P1')×A (front caliper piston area)×BF (front caliper efficiency factor)×r (effective radius of front caliper) / R (tire rolling radius) M 后 =(P1-P1')×A (rear caliper piston area)×BF (rear caliper efficiency factor)×r (effective radius of action of the rear caliper) / R (tire rolling radius) B. Feedback Control: The chassis domain controller calculates the reverse yaw torque that can provide stability control based on the difference between the ideal yaw rate ω0 and the actual yaw rate ω through PID control. The ideal yaw rate ω0 is calculated in real time based on the current vehicle speed, steering angle, body parameters, etc., while the actual yaw rate ω is collected in real time by the vehicle yaw rate sensor.

[0043] C. Drive Torque Output: The feedforward control output torque and the reverse yaw torque are calculated comprehensively. The final drive torque of each drive motor is determined through vector superposition, and the final drive torque is output to the PDCU. See details. Figure 3 ; D. When the slip ratio of the drive motor-controlled wheel exceeds the set limit E, the drive torque is reduced according to the set slope; when the slip ratio recovers to below the limit F, the original control strategy continues to be used; the set slope can be dynamically adjusted according to the current vehicle speed and road surface adhesion coefficient (such as dry road surface, icy and snowy road surface). For example, a smaller slope is used on low adhesion coefficient road surfaces to avoid wheel lock-up.

[0044] In one embodiment, the method further includes: emergency control in the event of brake failure based on the brake failure level, including: When the braking assist is insufficient, such as when the braking force loss is less than the set ratio (e.g., 20%), the braking failure level is considered minor, and only feedforward compensation is activated without triggering yaw control; the braking force loss is considered to be within the range of P. 正常 -P 失效 ) / P 正常 Calculate by multiplying by 100%, such as P. 正常 =80 bar, P 失效 =65 bar, braking force loss = 15 / 80×100% = 18.75% < 20%, which is judged as a minor fault. At this time, the yaw risk is low, and turning off the yaw control can reduce the calculation load. When the braking force loss is greater than or equal to 50% due to single-loop failure, the braking failure level is considered to be moderate, and feedforward control, feedback control, and slip ratio control are activated. At this time, the braking force loss = (dual-loop braking torque - single-loop braking torque) / dual-loop braking torque × 100%. The yaw risk is high at this time, and full-function activation is required. When dual circuits or multiple motors fail, the braking failure level is considered severe. In this case, pure electric braking, emergency warning, and intelligent driving linkage are activated, such as lane keeping for L3 vehicles. When dual circuits fail, the braking force is lost by 100%. Multi-motor failure refers to the failure of two or more drive motors. In this case, pure electric braking is required, and the highest level warning is triggered to ensure the safety of the driver and surrounding vehicles.

[0045] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0046] This invention also provides an emergency control system for distributed drive new energy vehicle braking failure, such as... Figure 1 As shown, it includes: Feedforward torque calculation module: This module calculates the reverse drive torque required to compensate for brake failure caused by a failed circuit or insufficient power assist, based on the brake failure type. It is integrated into the chassis domain controller. The chassis domain controller can communicate in real-time with the IPB and PDCU via the CANFD bus. Brake failure types are identified by signal IDs, such as single-loop failure signal ID=0x180, with a data length of 8 bytes. The third byte, Bits 0-1, indicates the brake failure type: 00 indicates no failure; 01 indicates left front + right rear failure; 10 indicates right front + left rear failure; and 11 indicates power assist failure. The CAN FD bus uses twisted-pair transmission, providing strong differential signal anti-interference capabilities and a communication distance ≤40m, meeting the vehicle wiring requirements. The bus load rate is ≤30%, ensuring priority transmission of torque signals and preventing blockage by other signals. Feedback torque calculation module: used to obtain the ideal yaw rate and the actual yaw rate of the vehicle, and calculate the reverse yaw torque through PID control algorithm to suppress unexpected yaw during braking; in one embodiment, it is integrated into the chassis control domain; the chassis control domain adopts the AUTOSAR architecture, and the feedback torque calculation module is an independent software component that interacts with the feedforward module and the integrated calculation module through RTE (runtime environment) to support modular upgrades; The integrated calculation module is used to calculate the final driving torque of each drive wheel based on the reverse driving torque and the reverse yaw torque; the final driving torque of each drive wheel is used to control the distributed drive motor to output the corresponding reverse driving force.

[0047] Figure 1 Each module communicates via a CAN FD bus with a communication rate of 8Mbps and a signal transmission delay of ≤5ms, ensuring the real-time performance of torque calculation and output. The calculation cycle of both the feedforward torque calculation module and the feedback torque calculation module is 10ms, which is synchronized with the sampling cycle of the chassis domain controller to avoid torque distribution errors caused by data asynchrony.

[0048] In one embodiment, when the braking failure type is IPB single-loop failure, the method for calculating the reverse driving torque includes: Based on the IPB master cylinder hydraulic signal P1 and the braking parameters of the front and rear brake circuits, calculate the corresponding reverse driving torque M of the front brake circuit. 前 The reverse driving torque M corresponding to the rear braking circuit 后 The drive motor on the brake failure side provides power to M. 前 With M 后 Equal reverse driving torque.

[0049] In one embodiment, the method for calculating the reverse driving torque includes: M 前 =P1×A 前 ×BF 前 ×r 前 / R; M 后 =P1×A 后 ×BF 后 ×r 后 / R; Mfront and Mrear represent the reverse driving torque corresponding to the front braking circuit and the reverse driving torque corresponding to the rear braking circuit, respectively. A 前 and A 后 : These represent the piston areas of the front caliper and the rear caliper, respectively; BF 前 and BF 后 : These represent the front caliper performance factor and the rear caliper performance factor, respectively; r 前 and r 后 : These represent the effective operating radius of the front caliper and the effective operating radius of the rear caliper, respectively; R: Tire rolling radius.

[0050] In one embodiment, when the braking failure type is assist failure, the method for calculating the reverse driving torque includes: Based on the output hydraulic pressure P corresponding to a certain input when the power is normal. 正常 When the power assist fails, the corresponding output hydraulic pressure P of the same input 失效The braking parameters of the front and rear braking circuits are calculated by providing reverse driving torque to the front and rear wheels through the drive motor.

[0051] In one embodiment, based on the stroke-hydraulic pressure mapping relationship, i.e., the corresponding curve (PS curve) of the input brake pedal stroke and output hydraulic pressure pre-stored in the controller, when the assist fails, the P value is obtained by querying this curve. 正常 With P 失效 The difference. The curve supports OTA upgrades. When the IPB system is repaired or replaced, the curve parameters can be updated via OTA, avoiding recalibration and improving maintenance convenience.

[0052] In one embodiment, when the brake pedal force is greater than 200N, the compensation torque is automatically increased by 10% to accommodate the driver's emergency braking intention. The brake pedal force is collected by a pedal force sensor with a measurement range of 0-1000N, an accuracy of ±5N, and a sampling frequency of 100Hz. When three consecutive sampling points are greater than 200N, the torque increase is triggered to avoid accidental triggering due to instantaneous force.

[0053] In one embodiment, if the master cylinder pressure sensor fails and the IPB master cylinder hydraulic signal P1j cannot be obtained, the hydraulic value is estimated using a brake pedal stroke-hydraulic mapping model pre-stored in the controller; for example, the estimated value of P1 corresponding to stroke S1 is: P1 正常 ×(S 实际 / S1), where P1 正常 and S 实际 In the brake pedal travel-hydraulic mapping model, this represents a pair of mapping values ​​that indicate the mapping relationship between the brake pedal travel and the hydraulic signal.

[0054] In one embodiment, the method further includes correcting the tire rolling radius R, wherein the correction method includes: R 修正 =R 标定 ×(1+0.01×Δ 胎压 -0.005 × wear degree), where Δ 胎压 Δ is the difference between the actual tire pressure and the standard tire pressure. 胎压 Data is collected via a tire pressure monitoring system (TPMS), which is a direct system with an accuracy of ±0.1 bar and updates data every 30 seconds. Wear level is estimated using the cumulative mileage from wheel speed sensors, e.g., 0.5% wear per 10,000 kilometers. The cumulative mileage is calculated by integrating the wheel speed signals and updated every 10 milliseconds, with an error of ≤±1% compared to the vehicle's odometer. Wear level = cumulative mileage × 0.05% / 1000 km. For example, with a cumulative mileage of 20,000 km, wear level = 20,000 × 0.05% / 1000 = 1%.

[0055] In one embodiment, the triggering condition for correcting the tire rolling radius R includes: automatically updating the tire rolling radius R when the tire pressure change is greater than a set percentage (e.g., 5%) or the wear degree is greater than a set percentage (e.g., 1%), in order to avoid torque calculation deviation.

[0056] In one embodiment, the method for calculating the reverse driving torque includes: M 前 =(P 正常 -P 失效 )×A 前 ×BF 前 ×r 前 / R M 后 =(P 正常 -P 失效 )×A 后 ×BF 后 ×r 后 / R A 前 and A 后 : These represent the piston areas of the front caliper and the rear caliper, respectively; BF 前 and BF 后 : These represent the front caliper performance factor and the rear caliper performance factor, respectively; r 前 and r 后 : These represent the effective operating radius of the front caliper and the effective operating radius of the rear caliper, respectively; M 前 and M 后 These are the required reverse driving torques for the front wheels and the rear wheels, respectively. R: Tire rolling radius.

[0057] In one embodiment, the method for calculating the final driving torque includes: The reverse driving torque output by the feedforward torque calculation module and the reverse yaw torque output by the feedback torque calculation module are vector-superimposed according to the corresponding drive wheels to obtain the final driving torque of each drive wheel and output to the PDCU.

[0058] The specific implementation of vector superposition here includes: when a single loop fails, such as when the left front + right rear loop fails, the left front drive wheel distributes the feedforward torque M. 前 +50% of the reverse yaw moment, feedforward moment M distributed to the right rear drive wheel 后 - 50% of the reverse yaw moment is used to counteract the yaw through the torque difference between the left and right wheels; when the power assist fails, the corresponding feedforward torque (M) is distributed to all four drive wheels. 前 / M 后 Distribute the load proportionally according to the axle load, and add 1 / 4 of the reverse yaw moment to uniformly suppress the overall yaw.

[0059] In one embodiment, a driving torque adjustment module is also included, which is used to monitor the wheel slip ratio in real time and adjust the driving torque according to the wheel slip ratio. The adjustment method includes: dynamically adjusting the driving torque when the wheel slip ratio exceeds a set limit.

[0060] In one embodiment, the slip ratio μ is calculated using the following formula: s=(v 车 -v 轮 ) / v 车 ×100%, where v 车 Through GPS and IMU fusion calculation, v 轮 Data is collected via wheel speed sensors; In one embodiment, for dry road surfaces, E=25% and F=20%; for wet and slippery road surfaces, E=20% and F=15%; and for icy and snowy road surfaces, E=15% and F=10%, and the system automatically switches between road surface types by recognizing the road surface type through a camera.

[0061] In one embodiment, the method for adjusting the driving torque according to the wheel slip ratio includes: when the slip ratio exceeds a set upper limit value, reducing the driving torque by a set slope.

[0062] In one embodiment, the high-adhesion road surface uses a slope of 50 N·m / ms to quickly suppress slippage; the low-adhesion road surface uses a slope of 20 N·m / ms to avoid power interruption caused by a sudden drop in torque.

[0063] In one embodiment, the method for adjusting the driving torque based on the wheel slip ratio further includes: restoring the final driving torque of each drive wheel when the wheel slip ratio falls below a set lower limit. For example, an exponential function curve is used to restore the torque, and the restoration formula includes: T(t)=T0×(1-e^(-t / τ)), τ=50ms, to avoid wheel impact caused by sudden torque changes.

[0064] In one embodiment, a failure detection module is also included, which is used to monitor the braking system status in real time, identify single-loop failure or booster failure of IPB, and generate a corresponding failure signal to send to the communication bus.

[0065] In one embodiment, the identification method includes: When the IPB master cylinder pressure sensor detects that the circuit pressure is less than the set pressure value of 0.5 bar for three consecutive cycles, it is initially determined to be faulty; further verification is carried out as follows: When the wheel speed sensor detects that the deviation between the wheel speed on the failed side and the theoretical value is greater than 20%, the signal consistency between the IPB controller and the chassis domain controller is further compared to rule out sensor failure.

[0066] In one embodiment, when the IPB controller sends a braking failure signal (such as a single-loop failure or power assist failure), the chassis domain controller compares the signal with its own judgment based on independent data: If the two judgments are consistent, for example, if the IPB reports a failure in the left front + right rear circuit, and the chassis domain controller detects abnormal wheel speeds in the left front / right rear wheels through the wheel speed sensors while the pressure in other circuits is normal, then it is determined that the same circuit has failed. Therefore, the failure signal is confirmed to be valid, and emergency control is triggered.

[0067] If the two judgments are inconsistent, for example, the IPB reports a failure, but the chassis domain controller does not find any abnormalities based on data such as wheel speed and pressure, then a secondary verification is initiated, such as resampling sensor data, checking the communication link, and eliminating false signals caused by the IPB controller itself, such as sensor false alarms or communication interference.

[0068] This dual-controller signal improves the accuracy of failure detection by introducing an independent judgment source, ensuring that the emergency control system only starts when a real failure occurs. This avoids safety risks caused by missed detections and prevents malfunctions from affecting normal driving.

[0069] In the failure detection module, the two controllers have distinct functions: the IPB controller, as the core controller of the intelligent integrated braking control system, directly monitors key states of the braking system, such as hydraulic pressure in each circuit, power assist motor status, and brake pedal travel, generating an initial braking failure signal based on circuit pressure. For example, when the IPB detects that the pressure in a certain circuit is consistently below a threshold (e.g., <0.5 bar), it will autonomously determine it as a single-circuit failure and generate a preliminary failure signal. The chassis domain controller, as the overall controller for the vehicle chassis system, receives signals from the IPB controller via the CAN bus and independently collects other vehicle status data, such as wheel speed sensor, yaw rate sensor, and drive motor status, and independently determines whether a braking system failure exists based on this data.

[0070] In one embodiment, a human-machine interaction module is also included, which is used to warn the driver when the brakes fail, including visual warnings and audible and visual warnings; the visual warnings include: displaying "Emergency brake activated, please keep steering stable" on the instrument panel and using a flashing red icon as a prompt; the audible and visual warnings include: a buzzer emitting a long beeping sound at a set frequency and the instrument cluster backlight flashing.

[0071] In one embodiment, an intelligent driving linkage module is also included, which, after the emergency control system is activated, triggers the following adjustments for the intelligent driving vehicle: Increase steering assist and limit the vehicle's steering angle to avoid oversteering; It automatically increases the following distance from the vehicle in front to allow more time for braking.

[0072] In one embodiment, the intelligent driving linkage module further includes the following adjustment: if the vehicle is still moving while the emergency control continues for a set duration (e.g., 10 seconds), a driver takeover request is triggered.

[0073] This invention also provides an emergency control method for a distributed-drive new energy vehicle when braking fails, comprising: Calculate the reverse driving torque required to compensate for the loss of braking force caused by the failure circuit or insufficient assist, based on the type of braking failure. The ideal yaw rate and the actual yaw rate of the vehicle are obtained, and the reverse yaw torque is calculated through the PID control algorithm to suppress the unexpected yaw during braking. Based on the reverse driving torque and the reverse yaw torque, the final driving torque of each drive wheel is calculated; the final driving torque of each drive wheel is used to control the distributed drive motor to output the corresponding reverse driving force.

[0074] In one embodiment, the X-type hydraulic circuit of the braking system includes circuit 1 consisting of left front and right rear, and circuit 2 consisting of right front and left rear. The IPB master cylinder pressure sensor has an accuracy of ±0.5 bar and a response time of <10 ms. When the IPB master cylinder pressure sensor detects a pressure of <0.5 bar in circuit 1 for three consecutive sampling cycles (30 ms), circuit 1 is determined to be faulty.

[0075] In one embodiment, wheel speed sensors are used for further verification. If the deviation of the left front / right rear wheel speed from the theoretical value is detected to be >20%, then loop 1 is considered to have failed. In one embodiment, the IPB sends a "loop 1 failure" signal via the CAN bus. Upon receiving this signal, the chassis domain controller initiates emergency control within 10ms. The right front / left rear wheels generate braking torque through IPB hydraulic braking: M 前 =P1×A 前 ×BF 前 ×r 前 / R; M 后 =P1×A 后 ×BF 后 ×r 后 / R; Left front motor compensation for left front hydraulic misalignment torque: M LF =M 前 ×m1; Right rear motor compensation for right rear hydraulic misalignment torque: M LF =M 后×m2; where m1 is a redundant parameter, with a value greater than 1, and 1.2 in this embodiment; m2 is the torque correction coefficient considering the load distribution of the rear axle; since the load ratio of the rear axle of passenger cars is usually lower than that of the front axle, and the load-bearing capacity of the rear axle drive motor is also lower than that of the front axle, the theoretically calculated braking torque M 后 The torque is adjusted so that the compensation torque of the rear axle motor matches the upper limit of the load corresponding to the rear axle load, thus avoiding overload; in this embodiment, it is 0.9.

[0076] Based on vehicle speed v Given the steering angle δ and the vehicle wheelbase L, the ideal yaw rate ω0 is calculated using a two-degree-of-freedom model. v ×δ / L; The actual yaw rate ω is collected in real time by the yaw rate sensor; the deviation Δω = ω0 - ω; The chassis domain controller calculates the reverse yaw moment through PID control: M z_feedback =K p ×Δω+ K i × +K d × ; K p K i K d Braking failure conditions were matched through actual vehicle calibration; in this embodiment, K p =1500,K i =80,K d =300; Based on vehicle dynamics, yaw moment needs to be achieved through the difference in torque between the left and right wheels: M z_feedback =((T fl -T fr )×B r ) / 2+((T rl -T rr )×B r ) / 2 Among them B f B r T represents the front / rear track width. fl T fr T rl T rr These are the driving torques for each wheel; Simplify the allocation strategy, ultimately the left front wheel bears the M load. z_feedback / 2, Right rear wheel bears -M z_feedback / 2, the lateral tendency is counteracted by the difference in torque between the left and right sides.

[0077] Calculate the final combined driving torque T fl_final and T rr_final : Left front wheel torque feedforward torque M 前 Superimposed with the feedback torque component: T fl_final =M 前 +M z_feedback / 2 Right rear wheel torque feedforward torque M 后 Superimposed with the feedback torque component: T rr_final =M 后 -M z_feedback / 2 The right front wheel and left rear wheel did not experience brake failure; they were only affected by the feedback torque: T fr_final =T rl_final =0, meaning only the failed side and the diagonal wheel participate in the compensation.

[0078] Assume M z_feedback =500 N·m, then the left front wheel increases by 250 N·m and the right rear wheel decreases by 250 N·m, generating a total yaw moment: Mz = (250 - (-250)) × B f / 2=250 / B f If B f =1.5m, then Mz=375N·m, effectively counteracting the swaying trend; The total driving torque of the left front wheel and the right rear wheel is M 前 +M 后 =2T b_fl It is equal to the original braking torque, maintaining the vehicle's braking deceleration unchanged.

[0079] In one embodiment, when the yaw rate sensor fails, the equivalent yaw rate is calculated using the wheel speed difference and steering angle. The calculation formula includes: ω 估算 =(v×δ / L)×(1+Δ 轮速 / Δv), where Δ 轮速 The left and right wheel speed difference is given by Δv, the vehicle speed change rate is given by δ, the steering angle is given by L, and the vehicle wheelbase is given by L.

[0080] This invention also provides a non-transitory computer-readable storage medium storing a computer program. The computer program includes program instructions that, when executed by a processor, implement the various steps of the method described in this invention, which will not be elaborated further here.

[0081] The computer-readable storage medium can be the data transmission apparatus or the internal storage unit of a computer device provided in any of the foregoing embodiments, such as the hard disk or memory of the computer device. The computer-readable storage medium can also be the external storage device of the computer device, such as the plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, etc. equipped on the computer device.

[0082] Furthermore, the computer-readable storage medium may include both internal storage units and external storage devices of the computer device. The computer-readable storage medium is used to store the computer program and other programs and data required by the computer device. The computer-readable storage medium may also be used to temporarily store data that is to be output or has already been output.

[0083] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0084] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0085] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0086] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0087] This invention also provides a computer program product, including a computer program / instruction, which, when executed by a processor, implements the steps of the emergency control method for brake failure in a distributed-drive new energy vehicle.

[0088] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

Claims

1. An emergency control system for brake failure in distributed-drive new energy vehicle models, characterized in that, include: Feedforward torque calculation module: used to calculate the reverse drive torque required to compensate for the loss of braking force based on the type of braking failure; Feedback torque calculation module: used to obtain the ideal yaw rate and the actual yaw rate of the vehicle, and calculate the reverse yaw torque through PID control algorithm; Comprehensive calculation module: used to calculate the final driving torque of each drive wheel based on the reverse driving torque and the reverse yaw torque.

2. The emergency control system for brake failure in a distributed-drive new energy vehicle as described in claim 1, characterized in that, When the braking failure type is IPB single-loop failure, the calculation method for the reverse driving torque includes: Based on the IPB master cylinder hydraulic signal P1 and the braking parameters of the front and rear brake circuits, calculate the corresponding reverse driving torque M of the front brake circuit. 前 The reverse driving torque M corresponding to the rear braking circuit 后 .

3. The emergency control system for brake failure in a distributed-drive new energy vehicle as described in claim 2, characterized in that, The method for calculating the reverse driving torque includes: M 前 =P1×A 前 ×BF 前 ×r 前 / R; M 后 =P1×A 后 ×BF 后 ×r 后 / R; M 前 and M 后 These represent the reverse driving torque corresponding to the front braking circuit and the reverse driving torque corresponding to the rear braking circuit, respectively. A 前 and A 后 : These represent the piston areas of the front caliper and the rear caliper, respectively; BF 前 and BF 后 : These represent the front caliper performance factor and the rear caliper performance factor, respectively; r 前 and r 后 : These represent the effective operating radius of the front caliper and the effective operating radius of the rear caliper, respectively; R: Tire rolling radius.

4. The emergency control system for brake failure in a distributed drive new energy vehicle as described in claim 1, characterized in that, When the braking failure type is assist failure, the calculation method for the reverse driving torque includes: Based on the output hydraulic pressure P corresponding to a certain input when the power is normal. 正常 When the power assist fails, the corresponding output hydraulic pressure P of the same input 失效 The braking parameters of the front and rear braking circuits are calculated by providing reverse driving torque to the front and rear wheels through the drive motor.

5. The emergency control system for brake failure in a distributed drive new energy vehicle as described in claim 4, characterized in that, The method for calculating the reverse driving torque includes: M 前 =(P 正常 -P 失效 )×A 前 ×BF 前 ×r 前 / R M 后 =(P 正常 -P 失效 )×A 后 ×BF 后 ×r 后 / R A 前 and A 后 : These represent the piston areas of the front caliper and the rear caliper, respectively; BF 前 and BF 后 : These represent the front caliper performance factor and the rear caliper performance factor, respectively; r 前 and r 后 : These represent the effective operating radius of the front caliper and the effective operating radius of the rear caliper, respectively; M 前 and M 后 These are the required reverse driving torques for the front wheels and the rear wheels, respectively. R: Tire rolling radius.

6. The emergency control system for brake failure in a distributed drive new energy vehicle as described in claim 1, characterized in that, The methods for calculating the final driving torque include: The reverse driving torque output by the feedforward torque calculation module and the reverse yaw torque output by the feedback torque calculation module are vector-superimposed according to the corresponding drive wheels to obtain the final driving torque of each drive wheel and output to the PDCU.

7. The emergency control system for brake failure in a distributed-drive new energy vehicle as described in claim 1, characterized in that, It also includes a drive torque adjustment module, which is used to adjust the drive torque according to the wheel slip ratio. The adjustment method includes: adjusting the drive torque when the wheel slip ratio exceeds the set limit.

8. The emergency control system for brake failure in a distributed drive new energy vehicle as described in claim 7, characterized in that, Methods for adjusting driving torque based on wheel slip ratio include: When the slip ratio exceeds the set upper limit, the driving torque is reduced by the set slope.

9. The emergency control system for brake failure in a distributed drive new energy vehicle as described in claim 7 or 8, characterized in that, The method of adjusting the driving torque based on the wheel slip ratio also includes: when the wheel slip ratio falls below a set lower limit, restoring the final driving torque of each drive wheel.

10. An emergency control method for a distributed-drive new energy vehicle in case of braking failure using the system as described in claim 1, characterized in that, include: Calculate the reverse driving torque required to compensate for the loss of braking force based on the type of braking failure. The ideal yaw rate and the actual yaw rate of the vehicle are obtained, and the reverse yaw moment is calculated through a PID control algorithm. Calculate the final driving torque of each drive wheel based on the reverse driving torque and the reverse yaw torque.

11. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the emergency control method for brake failure in a distributed-drive new energy vehicle as described in claim 10.

12. A computer program product comprising a computer program / instructions, characterized in that, When the computer program / instruction is executed by the processor, it implements the steps of the emergency control method for brake failure in a distributed-drive new energy vehicle as described in claim 10.

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